Dental paste dispensing device and method of use

ABSTRACT

A dental paste dispensing device having a modified dispensing end for atraumatic contact with soft tissue is disclosed. The dispensing device includes a needle having a dispensing end with a terminal edge for dispensing the dental paste to a location in a patient mouth containing soft tissue, wherein the dispensing end includes an atraumatic modification. The modification comprises one of a non-metal coating on an outer surface of the dispensing end, a plastic tip member over the dispensing end, or a decreasing diameter at the terminal edge from a first point on the outer surface to a distal-most point of the outer surface.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of co-pending U.S. patent applicationSer. No. 13/214,933 filed Aug. 22, 2011 and entitled DENTAL PASTEDISPENSING DEVICE AND METHOD OF USE, the disclosure of which isincorporated herein by reference in its entirety as if completely setforth herein below.

FIELD OF THE INVENTION

This invention relates to a dispensing device for use in delivering apaste in a dental procedure.

BACKGROUND OF THE INVENTION

The restoration of a patient's tooth or teeth often includes thereplacement of natural tooth structure by a manufactured dentalrestoration or dental prosthesis. Typically, a tooth that is to berestored is first prepared by a dentist to remove undesired toothsubstance and to provide the tooth with a shape appropriate to receivethe dental restoration. The dental restoration is typically matedprecisely with the remaining tooth shape prepared by the dentist on thebasis of an impression of the prepared tooth. Therefore the dentalimpression should be very precise, and should represent all toothstructure required to determine the shape of the mating surface of thelater dental restoration. In particular, the dental impression shouldrepresent the transition or the “margin” between the shape prepared in atooth and the natural tooth shape. For dental restorations that extendbelow a patient's gingiva (or gums), the dentist also should make thepart of the margin accessible for the dental impression that wouldnormally be covered by the gingiva. The procedure of displacing thegingiva from the tooth to make the margin accessible is also known as“gingival retraction” in the field of dentistry.

A common gingival retraction procedure includes the insertion of aretraction cord in the gingival sulcus, which displaces the gingiva fromthe tooth. However, the insertion of a retraction cord is relativelytime consuming and is generally perceived as being relativelyinconvenient for the dentist and uncomfortable for the patient. Analternative for the retraction cord is a gingival retraction paste,which is typically a high viscosity paste that is squeezed or injectedinto the gingival sulcus, thereby displacing the soft gingival tissuefrom the tooth. The gingival retraction paste in one example is providedin a syringe or applicator that is connectable with a metal dispensingcannula or needle. The cannula or needle dispenses the paste around atooth towards the entry of the gingival sulcus to thereby squeeze itinto the gingival sulcus.

However, soft tissue in the mouth is very sensitive and trauma to thetissue can occur when a metal device makes contact. This issue may alsooccur in other dental procedures besides gingival retraction, wheredental paste is being applied in a region containing soft tissue thatmay be contacted by the dispensing end of the device. There is thus aneed for an improved dispensing device for providing dental paste to aregion with soft tissue.

SUMMARY OF THE INVENTION

The present invention provides a dental paste dispensing device having amodified dispensing end for atraumatic contact with soft tissue. To thatend, in one embodiment, the dispensing device comprises a needle havinga dispensing end with a terminal edge for dispensing the dental paste toa location in a patient mouth containing gingival tissue. The dispensingend has a decreasing diameter at the terminal edge from a first point onthe outer surface to a distal-most point of the outer surface forlaterally displacing the gingival tissue atramatically to permit thedental paste to be dispensed into the givigival sulcus.

In another embodiment, the dispensing device comprises a metal needlehaving an attachment end adapted to be attached to a capsule containingthe dental paste and a dispensing end with a terminal edge fordispensing the dental paste to a location in a patient mouth containingsoft tissue, wherein the dispensing end includes a modification foratraumatic contact with the soft tissue. The modification comprises oneof a non-metal coating on an outer surface of the dispensing end, aplastic tip member over the dispensing end, or a decreasing diameter atthe terminal edge from a first point on the outer surface to adistal-most point of the outer surface. In one embodiment, the metalneedle has a dispensing end coated with a rubbery material. In anotherembodiment, the metal needle has a rounded or slanted terminal edge atthe dispensing end. In yet another embodiment, the metal needle includesa plastic tip attached thereto having an inner channel with a flattenedoval shape in a static position and a rounded shape in a dynamicposition with sidewall bumps adjacent the inner channel for displacingsoft tissue.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate embodiments of the invention and,together with a general description of the invention given above, andthe detailed description given below, serve to explain the invention.

FIG. 1 is a perspective view of a dispensing applicator having adetachable carrier and body.

FIG. 2 is a perspective view of a detachable carrier.

FIG. 3 is a side view of the carrier of FIG. 2.

FIG. 4 is a top view of the carrier of FIG. 2.

FIG. 5 is a cross-sectional view taken along line 5-5 of FIG. 3.

FIG. 6 is a bottom view of the carrier of FIG. 2.

FIG. 7 is a front view of the carrier of FIG. 2.

FIG. 8 is a rear view of the carrier of FIG. 2.

FIG. 9 is a side view of a capsule and needle according to oneembodiment.

FIG. 10 is a cross-sectional view taken along line 10-10 of FIG. 9.

FIG. 11 is a cross-sectional view of a needle according to anotherembodiment.

FIG. 12 is a cross-sectional view of a needle according to anotherembodiment.

FIG. 13 is a top view of a needle with plastic tip according to anotherembodiment.

FIG. 14 is a side view of the needle with plastic tip of FIG. 13.

FIG. 15 is an end view of the needle with plastic tip, in the staticposition, taken along line 15-15 of FIG. 14.

FIG. 16 is an end view of the needle with plastic tip, in the dynamicposition.

DETAILED DESCRIPTION

In accordance with embodiments of the invention, the shape, material,and/or dimensions of the needle tip of a dispensing device may help toavoid damage to soft tissue during use of the device of the invention ina patient's mouth. One use is a gingival retraction procedure in whichthe device dispenses dental paste into the gingival sulcus between atooth and the gums (gingiva). The invention also may allow the dentalpaste to be inserted relatively deep into the gingival sulcus, withoutcausing trauma to the soft tissue. Deep penetration of the dental pastein the gingival sulcus may help to effectively retract the gingiva froma tooth, and consequently may help to provide an acceptable impressionparticularly of a preparation margin of a tooth. Other dental proceduresmay likewise involve application of a dental paste to oral locationswith soft tissue, whereby a modification to the needle tip in accordancewith the invention prevents trauma to the soft tissue.

FIG. 1 is a perspective view of a dispensing applicator 10 for use indispensing a flowable material (i.e., dental paste) in a dentalprocedure. The applicator 10 includes a body 12 with gears, which bodymay be anatomically designed for easy gripping by the hand andconvenient squeezing of trigger 14 to actuate a piston 16 for dispensingdental paste, with a force advantage, for example, of at least 9 to 1.The applicator 10 further includes a detachable carrier 20 for receivinga capsule 22 containing the dental paste, such as a gingival retractionmaterial. In one embodiment, the carrier 20 is detached from the body 12by screwing. The piston 16 extends through body 12 and is received in achamber 24 of carrier 20 to engage a capsule 22 residing therein foradvancing the dental paste. The capsule 22 includes a cannula or needle30 terminating distally in an end that serves as a dispensing end 32 forapplicator 10 from which the dental paste may be dispensed.

FIGS. 2-8 describe a carrier 20 for attachment to body 12 and whichincludes chamber 24 for receiving a capsule 22. The carrier 20 mayinclude a slot or groove 26 for receiving a mating member 28 of capsule22, and which prevents the capsule 22 from falling off. In oneembodiment, the carrier 20 may be used for two different lengths offilled capsules 22. In one embodiment, the carrier is detachable fromthe body of the applicator.

In one embodiment, the capsule 22 is filled with paste for dental use.The device 10 may use a capsule 22 having an integrated needle 30 madeof the same plastic material as the capsule 22, as depicted in FIG. 1,and which may or may not be removable. The needle 30 made of plasticprovides an atraumatic contact with soft tissue, as opposed to a metalneedle. The plastic needle 30 can thus be used in a gingival retractionprocedure for displacing the gingiva laterally without trauma to thegingiva, and thereby allowing for delivery of the retraction paste deepinto the gingival sulcus. Alternatively, the needle 30 may be removableand of a different material than the capsule 22, such as a metal needle.The needle 30 may extend at an angle from the capsule 22, eitherstraight or curved, or may be co-aligned and/or parallel with an axis ofthe capsule 22. The configuration may be selected for suitability inreaching certain locations in a patient's mouth.

FIG. 9 depicts an atraumatic design for a needle 30 adapted to beattached to a capsule 22 according to an embodiment of the invention fordelivering paste material for dental use. FIG. 10 is a cross-sectionalview taken along line 10-10 of FIG. 9. In one embodiment, the capsule 22has a metal needle 30 that is permanently attached. In one embodiment,the capsule 22 has a metal needle 30 that is temporarily (removably)attached by means of screw-on, click-on or click-and-twist-onimmediately before use. The dispensing end 32 of the metal needle 30includes a non-metal coating 34, for example of a rubbery material. Therubbery material can prevent tissue trauma when it is in contact withsoft tissue in a dental procedure. In one embodiment, the capsule 22 hasa number of wings 36 for ease of twist. In one embodiment, the capsule22 is used with a dispensing applicator, such as applicator 10 of FIG.1.

The non-metal coating 34 may be spray-coated, dip-coated, or over-moldedonto the dispensing end 32, and advantageously covers the terminal edgeof the metal needle 30, so that upon contact with the soft tissue, nometal touches the soft tissue. Any other suitable means of applying anon-metal coating 34 to a metal needle 30 may be employed other than themeans recited above, whether now known or hereafter developed. Thenon-metal coating 34 may be a rubbery material, such as natural orsynthetic rubber, polyethylene, polyethylene propylene, or any otherelastomer suitable for use in an oral environment.

FIG. 11 is a cross-sectional view of an alternative atraumaticconfiguration for the dispensing end 32 of a metal needle 30. The needlewall 38 may taper inwardly in diameter approaching the dispensing end 32and terminates in a rounded edge 32 a. Thus, an inner diameter ID₁adjacent a proximal attachment end (not shown) of the needle 30 thatattaches to the capsule 22 may be greater than an inner diameter ID₂ atthe opposing distal dispensing end 32 Likewise, an outer diameter OD₁adjacent the attachment end of the needle 30 may be greater than anouter diameter OD₂ at the dispensing end 32. At the terminal edge 32 aof the needle 30, i.e., the distal-most portion of the needle 30, theouter surface tapers inwardly in curved fashion, i.e., the outerdiameter OD₂ decreases non-linearly to a smaller diameter at theterminal edge 32 a. In one embodiment, the outer diameter OD₂ decreasesgradually until reaching the inner diameter ID₂ such that only the outersurface of the needle 30 is radiused at the terminal edge 32 a. Inanother embodiment, the inner surface also tapers outwardly in curvedfashion, i.e., the inner diameter ID₂ increases non-linearly as theouter diameter OD₂ decreases non-linearly until an intermediate diameteris reached, such that the terminal edge 32 a is radiused both on theinner and outer surfaces of the needle 30. The smaller diameters ID₂/OD₂and rounded terminal edge 32 a provide a non-traumatic dispensing end 32a when in contact with soft tissue in the mouth, and can thus permit theneedle 30 to contact the gingiva and displace it laterally to inject thedental paste into the gingival sulcus. Because the terminal edge 32 a isrounded, i.e., it has a radius with no sharp corners, it gently slidesagainst the soft tissue, and in particular can slide between a tooth andthe gum, without harshly engaging the soft tissue, thereby allowing forthe dental paste to be dispensed deeply into the gingival sulcus. It maybe appreciated, that the rounded edge 32 a alone provides an atraumaticdispensing end 32 for needle 30, such that a constant diameter needlewall 38 is also contemplated, with the diameter of the needle varyingonly at the terminal edge 32 a.

FIG. 12 is a cross-sectional view of yet another alternative atraumaticconfiguration for the dispensing end 32 of a metal needle 30. As withthe needle 30 of FIG. 11, the needle wall 38 may taper inwardly indiameter approaching the dispensing end 32, such that the inner diameterID₁ and an outer diameter OD₁ may be greater than the inner diameter ID₂and outer diameter OD₂, respectively. The needle 30, however, terminatesin a straight angled, inwardly slanted edge 32 b formed by the OD₂linearly decreasing until becoming essentially equal to the ID₂ at thedispensing end 32. In other words, the terminal edge 32 b of the needle30 slants inwardly from the outer diameter OD₂ to the inner diameterID₂, thereby forming an inwardly slanted terminal edge 32 b for theneedle 30. The inwardly slanted terminal edge 32 b of the dispensing end32 provides a non-traumatic dispensing end 32 when in contact with softtissue in the mouth, and can thus permit the needle 30 to contact thegingiva and displace it laterally to inject the dental paste into thegingival sulcus. Because the terminal edge 32 b is slanted, uponcontacting the soft tissue with the edge 32 b, the soft tissue gentlyslides along the slanted edge 32 b rather than being harshly engaged byit, allowing the dispensing end 32 to slip gently between the tooth andgums for dispensing the dental paste deeply into the gingival sulcus.Again, a needle wall 38 of constant diameter from the attachment end tothe slanted terminal edge 32 b of the dispensing end 32 is contemplated,with the slanted terminal edge 32 b providing an atraumatic dispensingend 32.

Both FIGS. 11 and 12 generally disclose a modification to a metal needle30 in which the outer surface decreases in diameter at the dispensingend 32, from a first point to a second distal-most point. The decreasein diameter can be non-linear to provide the radiused terminal edge 32a, or linear to provide the slanted terminal edge 32 b, eithermodification providing an atraumatic dispensing end 32 for contactingsoft tissue in a dental procedure. In addition, or alternatively, thedispensing end 32, including the terminal edge 32 a, 32 b, can be coatedwith a non-metal coating 34, as shown in FIGS. 9 and 10, in particular arubbery material, to provide an atraumatic modification to thedispensing end 32 of a metal needle 30.

FIGS. 13-16 detail yet another alternative atraumatic configuration forthe dispensing end 32 of a metal needle 30. A plastic tip 40 is placedover the dispensing end 32 of needle 30. The plastic tip 40 includes afirst inner channel 42 sized to fit securely over the dispensing end 32of needle 30 and is attached thereto. A second inner channel 44 thenforms the dispensing end 46 of the plastic tip 40, and is advantageouslyslightly larger than the inner diameter ID₂ of the needle 30 to avoidrupturing the plastic tip when a dental paste is extruded through thedispensing ends 32 and 46. Sidewall bumps 48, 50 are provided on eitherside of the second inner channel 44. In the static (i.e.,non-dispensing) position, shown in end view in FIG. 15, the second innerchannel 44 forms a flattened oval shape. In the dynamic (i.e.,dispensing) position, shown in end view in FIG. 16, the second innerchannel 44 adapts to a round shape with the sidewall bumps 48, 50protruding therefrom. The sidewall bumps 48, 50 assist with pushing thegingiva away from the tooth laterally in a non-traumatic fashion, sothat the dental paste is guided into the gingival sulcus.

FIGS. 9-16 are described with reference to a metal needle 30; however,the invention is not so limited. The modifications to the dispensing end32 of a needle 30 may also be employed with a plastic needle to furtherensure atraumatic delivery of a dental paste. However, thesemodifications may not be considered necessary, as a plastic material mayby itself be sufficiently atraumatic when contacting soft tissue, suchas the gingiva during gingival retraction.

While the present invention has been illustrated by the description ofone or more embodiments thereof, and while the embodiments have beendescribed in considerable detail, they are not intended to restrict orin any way limit the scope of the appended claims to such detail.Additional advantages and modifications will readily appear to thoseskilled in the art. The invention in its broader aspects is thereforenot limited to the specific details, representative apparatus and methodand illustrative examples shown and described. Accordingly, departuresmay be made from such details without departing from the scope of thegeneral inventive concept.

What is claimed is:
 1. A dental paste dispensing device, comprising: ametal needle having an attachment end adapted to be attached to acapsule containing the dental paste and a dispensing end with a terminaledge for dispensing the dental paste to a location in a patient mouthcontaining soft tissue, wherein the dispensing end includes amodification for atraumatic contact with the soft tissue, where themodification comprises one of a non-metal coating on an outer surface ofthe dispensing end, a plastic tip member over the dispensing end, or adecreasing diameter at the terminal edge from a first point on the outersurface to a distal-most point of the outer surface.
 2. The dispensingdevice of claim 1, wherein the modification is the non-metal coating ofa rubbery material.
 3. The dispensing device of claim 1, wherein themodification is the plastic tip member comprising a first inner channelengaged over the dispensing end and a second inner channel of largersize than an inner diameter of the dispensing end, where the secondinner channel has a flattened oval shape in a static position and arounded shape in a dynamic position.
 4. The dispensing device of claim3, wherein the plastic tip member further includes a pair of opposedsidewall bumps adjacent and protruding outwardly from the second innerchannel for displacing gingiva during delivery of the dental paste. 5.The dispensing device of claim 1, wherein the modification is thedecreasing diameter at the terminal edge, where the decrease isnon-linear to form a rounded terminal edge.
 6. The dispensing device ofclaim 1, wherein the modification is the decreasing diameter at theterminal edge, where the decrease is linear to form an inwardly slantedterminal edge.
 7. The dispensing device of claim 1 further comprising: acapsule for containing the dental paste, wherein the attachment end ofthe metal needle is attached to the capsule for receiving the dentalpaste into the metal needle.
 8. The dispensing device of claim 7 whereinthe attachment end of the needle is permanently attached to the capsule.9. The dispensing device of claim 7 wherein the attachment end of theneedle is removably attached to the capsule.
 10. The dispensing deviceof claim 7, further comprising: an applicator body including a pistonand a trigger mechanism for advancing the piston; and a carrier attachedat a first end to the applicator body and having a channel therein inwhich the capsule is positioned for engagement proximate the first endwith the piston and having the metal needle extending from a second enddistal of the first end for dispensing the dental paste from the capsulethrough the needle to the dispensing end.
 11. A dental paste dispensingdevice for dispensing a dental composition into a gingival sulcus, thedevice comprising: a needle having a dispensing end with a terminal edgefor dispensing the dental paste to a location in a patient mouthcontaining gingival tissue, wherein the dispensing end has a decreasingdiameter at the terminal edge from a first point on the outer surface toa distal-most point of the outer surface for laterally displacing thegingival tissue atramatically to permit the dental paste to be dispensedinto the givigival sulcus.
 12. The dispensing device of claim 11,wherein the decreasing diameter at the terminal edge is non-linear toform a rounded terminal edge.
 13. The dispensing device of claim 11,wherein the decreasing diameter at the terminal edge is linear to forman inwardly slanted terminal edge.
 14. The dispensing device of claim11, further comprising: an applicator body including a piston and atrigger mechanism for advancing the piston; and a carrier attached at afirst end to the applicator body and having a channel therein forreceiving a capsule containing the dental composition, the channelpositioned for engagement proximate the first end with the piston andhaving the needle extending from a second end of the applicator bodydistal of the first end for dispensing the dental paste from the capsulethrough the needle to the dispensing end.
 15. The dispensing device ofclaim 11 further comprising: a capsule for containing the dental pastecoupled to the needle, and a piston for engagement with the capsule foradvancing the dental paste into the metal needle toward the dispensingend.
 16. The dispensing device of claim 15 wherein the needle is fixedlyattached to the capsule.
 17. The dispensing device of claim 16 whereinthe needle and the capsule are made of different materials.
 18. Thedispensing device of claim 16 wherein the needle and the capsule aremade of the same material.
 19. The dispensing device of claim 15 whereinthe dispensing end is angled relative to a longitudinal axis of thecapsule.
 20. The dispensing device of claim 15 wherein the capsule ismade of a plastic material and the needle is made of metal and isremovably coupled to the capsule.